Deans_whole_thesis_ex_pub_mat.pdf (48.9 MB)
Isolation of plant natural products of potential chemotaxonomic significance and medicinal value
thesisposted on 2023-05-28, 09:48 authored by Bianca DeansBianca Deans
This thesis reports on the application of a rapid and simple pressurised hot water extraction (PHWE) method that utilises an unmodified household espresso machine to extract structurally-diverse natural products from plant material. The core focus of this thesis was the use of PHWE to expedite phytochemical screening of native Tasmanian and Australian plants and facilitate natural product isolation. The introduction features reviews on two key topics that are pertinent to the research described in this thesis. The first review summarises all natural product isolation studies of endemic Tasmanian vascular plants, which provides context for subsequent studies. The second review provides an overview of the applications of accelerated solvent extraction (ASE‚Äövë¬¢) and PHWE methods for the isolation of natural products. PHWE was employed to develop phytochemical profiles of several endemic Tasmanian Proteaceae members. This includes the identification of novel arbutin derivatives in ancient Tasmanian Proteaceae genera that may represent potential chemical markers. The phytochemical profiles of endemic Tasmanian Lomatia species were also studied. PHWE enabled the rapid and effective extraction and isolation of gram-scale quantities of the glycoside asperuloside from the native Australian Coprosma quadrifida. In addition, PHWE was employed to extract the leaf material of Australian carob cultivars, from which a novel tannic acid derivative was isolated. Natural product isolation studies of the native Australian Dodonaea viscosa using PHWE and traditional maceration afforded various ent-labdane diterpenoids. PHWE of Myoporum montanum was also identified as an effective tool for the isolation of known furanosesquiterpenoids. The rapid PHWE method facilitated the extensive sampling of Tasmannia lanceolata (Tasmanian native pepper) across diverse wild Tasmanian populations. Notably, this work identified the presence of two distinct chemotypes of drimane sesquiterpenoids.
Rights statementCopyright 2019 the author Chapter 1 includes the following published article: Deans, B. J., de Salas, M., Smith, J. A., Bissember, A. C., 2018. Natural products isolated from endemic Tasmanian vascular plants, Australian journal of chemistry, 71(10), 756‚Äö-767 Chapter 2 includes the following published article: Deans, B. J., Tedone, L., Bissember, A. C., Smith, J. A., 2018. Phytochemical profile of the rare, ancient clone Lomatia tasmanica and comparison to other endemic Tasmanian species L. tinctoria and L. polymorpha, Phytochemistry, 153, 74-78 Chapter also 2 includes the following published article: Deans, B. J., Kilah, N. L., Jordan, G. J., Bissember, A. C., Smith, J. A., 2018. Novel arbutin derivatives isolated from ancient Proteaceae: potential phytochemical markers present in Bellendena, Cenarrhenes and Persoonia genera, Journal of natural products, 81(5), 1241‚Äö-1251 Chapter 3 includes the following published article: Deans, B. J., Bissember, A. C., Smith, J. A., 2016. Practical isolation of asperuloside from Coprosma quadrifida via rapid pressurised hot water extraction, Australian journal of chemistry, 69(11), 1219‚Äö-1222 Chapter 3 also includes the following published article: Deans, B. J., Skierka, B. E., Karagiannakis, B. W., Vuong, D., Lacey, E., Smith, J. A., Bissember, A. C., 2018. Siliquapyranone: a tannic acid tetrahydropyran-2-one isolated from the leaves of carob (Ceratonia siliqua) by pressurised hot water extraction, Australian journal of chemistry, 71(9), 702‚Äö-707 Chapter 4 includes the following published article: Deans, B. J., Olivier, W. J., Girbino, D., Bissember, A. C., Smith, J. A., 2017. Extraction of carboxylic acid-containing diterpenoids from Dodonaea viscosa via pressurised hot water extraction, Fitoterapia, 126, 65‚Äö-68 Chapter 4 also includes a post print equivalent of an article published as: Deans, B. J., Just, J., Tedone, L., Kilah, N. L., Jordan, G. J., Bissember, A. C., Smith, J. A., 2020. Distinct drimane chemotypes in Tasmanian mountain pepper (Tasmannia lanceolata): differences in the profiles of pungent leaf phytochemicals associated with altitudinal cline, Journal of agricultural and food chemistry, 68(1), 315-322